Multi-speed gearbox

ABSTRACT

A multi-stage transmission which has a sun gear of a fourth planetary gear set connected with the housing in a non-rotatable manner, a ring gear of a first planetary gear set is permanently connected with a ring gear of the fourth planetary gear set, a sun gear of the first planetary gear set can be coupled with the housing via a first brake, a carrier of the first planetary gear set can be coupled with the housing via a second brake, the input drive shaft can be coupled with sun gear of the first planetary gear set via a first clutch, and the drive shaft can be coupled with a carrier of the fourth planetary gear set via a second clutch. Variations of other couplings within the multi-stage transmission result in transmissions having similar properties.

This application is a National Stage completion of PCT/EP2013/055062filed Mar. 13, 2013, which claims priority from German patentapplication serial no. 10 2012 207 091.5 filed Apr. 27, 2012.

FIELD OF THE INVENTION

The invention relates to a multi-speed gearbox in planetary design, inparticular for a motor vehicle.

BACKGROUND OF THE INVENTION

Such multi-speed gearboxes are mainly used as automatic transmissions ofmotor vehicles wherein the effective power flow in the respective gearstep is defined by a targeted actuation of the shift element within theplanetary set. In addition, the planetary sets in an automatictransmission are usually connected with a start-up element subject to aslip effect and alternatively provided with a bypass clutch, as forexample a hydrodynamic torque converter or a hydraulic clutch.

A multi-speed gearbox in planetary design is known from DE 10 2008 000428 A1 in which four planetary sets as well as a total of eightrotatable shafts are disposed in a housing, of which one constitutes theinput drive shaft and the other the drive shaft of the multi-speedgearbox. Furthermore, at least six shift elements are provided in thearea of the shafts by the targeted actuation of which the power flowwithin the four planetary sets varies and thus different transmissionratios are definable between the input drive shaft and the drive shaft.Hereby it is possible to shift into a total of nine forward gears aswell as one reverse gear.

SUMMARY OF THE INVENTION

The object of the invention is to disclose an alternative multi-speedgearbox, preferably with an improved degree of efficiency andsufficiently greater and sufficiently evenly distributed transmissionratio range.

The object of the invention is achieved by means of a multi-speedgearbox comprising at least four planetary sets, a housing, an inputdrive shaft and a drive output shaft, in which

-   -   a sun gear of the fourth planetary gear set connected with the        housing in a rotatably fixed manner,    -   a ring gear of a first planetary gear set is permanently        connected with a ring gear of the fourth planetary gear set,    -   a sun gear of the first planetary gear set can be coupled with        the housing via a first brake,    -   a carrier of the first planetary gear set can be coupled with        the housing via a second brake,    -   the input drive shaft can be coupled with the sun gear of the        first planetary gear set via a first clutch,    -   the drive shaft can be coupled with a carrier of the fourth        planetary gear set via a second clutch and four of the following        six connections and two of the above connections are implemented        to be detachable by means of at least one shift element:    -   connection of the input drive shaft with a sun gear of a second        planetary gear set,    -   connection of the input drive shaft with a carrier of a third        planetary gear set,    -   connection of the drive shaft with a ring gear of the third        planetary gear set,    -   connection of the ring gear of the first planetary gear set with        a sun gear of the third planetary gear set,    -   connection of the carrier of the first planetary gear set with a        ring gear of the second planetary gear set and    -   connection of the ring gear of the first planetary gear set with        a carrier of the second planetary gear set,

In particular, a gear set is understood to be a planetary gear set; itcomprises at least one sun gear with which one or more planetary gearsmesh, a carrier which determines the axes of the planetary gears and aring gear with which the planetary gears mesh. Preferably, the ring gearhas an inner gearing and the sun gear an outer gearing.

One advantage of the invention can be that the shift elements of themulti-speed gearbox, that is, the transmission-side brakes and coupling,are easily accessible from the outside. Thus, the actuators, for exampleelectric motors, hydraulic valves, hydraulic pumps and the like, can bedisposed in the vicinity of the shift elements, whereby mechanicaland/or hydraulic losses can be diminished and less energy can benecessary for the actuation of shift elements. Also, less energy isneeded to maintain the shift element in its current operating state,that is, disengaged or engaged, respectively, for example, because thelosses in pressure are less as well as a result of short lines. It isalso possible to dispose the shift elements on the housing, so they areat least partially rotationally fixed, by means of which, seals thatconnect a standing line with a rotating line can be completely orpartially avoided.

The spatial configuration of easily accessible shift elements simplifiesthe usual replacement of hydraulically actuated lamellar clutches orbrakes by electromechanically or electrohydraulically actuated brakesand clutches, that are comparatively easy to control as needed. Easilyaccessible shift elements are, on the one hand, brakes that couple ashaft with the housing in a rotatably fixed manner, but, on the otherhand, are shift elements on the outer lying shafts of the multi-speedgearbox, preferably an input or output shaft to which the hydraulicfluid required for actuation can be supplied comparatively easily.

Besides this property, the multi-speed gearbox also has a good degree ofgearing efficiency, only little stress on component parts, especiallylow planetary set and shift element torque, low absolute and relativespeeds of rotation and/or low construction costs. The latter makespossible the implementation of the multi-speed gearbox of little weightand low costs. Finally, the multi-speed gearbox enables a goodtransmission ratio range, thus a very serviceable stepping of the gears.

In general, a preferred embodiment of the multi-speed gearbox comprisesfour planetary gear sets, four clutches, two brakes and a fixed couplingof the housing.

Through actuation of two shift elements, respectively (brakes and/orclutches) nine forward gears and one reverse gear can be engaged,wherein three other alternative shift positions are available for thefourth gear.

A hydrodynamic torque converter, a hydrodynamic clutch, and additionalstart-up clutch, an integrated start-up clutch or brake and/or anadditional electric machine can serve as start-up elements.

In principle, an electric machine or other power/energy source can bedisposed on each shaft. Furthermore, a freewheel can be disposed on eachshaft, basically for the housing or for another shaft.

Preferably the multi-speed gearbox is implemented as a standard drive,but a front-traverse design is also conceivable.

All shift elements can act in a friction- or form-locking manner.Preferably the first clutch and/or the third clutch (in othertransmission variants the seventh or the eighth instead of the thirdclutch), however, are implemented as form-locking clutches, especiallyas claw clutches, which leads to a clearly improved effectiveness andthereby clear advantages in use.

As a result it is understood that the first and third clutch (or theseventh/eighth clutch) needs to be actuated only once with shifting fromthe first into the ninth gear and that therefore these shift elementsare especially suited to be implemented as a claw clutch. It is thusalso understood that with these shift elements the advantage of thebetter degree of effectiveness prevails over the disadvantage of themore difficult handling because of their comparatively seldomactivation. In particular it is understood that the actuation of bothshift elements can take place in comparatively high gears, whereby thedifference of rotational speeds of the shafts can be small and thusfavorable for the actuation of the claw clutch.

The geometric position (sequence) of the individual gear set and shiftelements is freely selectable, as long as it allows the elements to becombined. The individual elements can thus be shifted in their positionat will.

Further advantageous variants of the multi-speed gearbox result from thedescription in overview with the drawings. Functionally, these have thesame properties as the main system, in particular similar degree ofeffect, similar stepping etc.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the invention this will be more preciselyexplained by means of the following drawings.

They are, in greatly simplified schematic representation:

FIG. 1 a first schematically depicted exemplary variant of a multi-speedgearbox according to the invention;

FIG. 2 a second schematically depicted exemplary variant of amulti-speed gearbox according to the invention;

FIG. 3 a third schematically depicted exemplary variant of a multi-speedgearbox according to the invention;

FIG. 4 a fourth schematically depicted exemplary variant of amulti-speed gearbox according to the invention;

FIG. 5 a fifth schematically depicted exemplary variant of a multi-speedgearbox according to the invention;

FIG. 6 a sixth schematically depicted exemplary variant of a multi-speedgearbox according to the invention;

FIG. 7 a seventh schematically depicted exemplary variant of amulti-speed gearbox according to the invention;

FIG. 8 an eighth schematically depicted exemplary variant of amulti-speed gearbox according to the invention;

FIG. 9 a ninth schematically depicted exemplary variant of a multi-speedgearbox according to the invention and

FIG. 10 a table that shows the engaged shift elements for thetransmission variant illustrated in FIG. 1 in each gear step.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

By way of introduction it should be noted that the same parts areprovided with the same reference numbers or same part designations inthe differently described embodiments so that the disclosures containedin the whole description can be correspondingly applied to the partswith the same reference numbers or same part designations. The chosenspecifications of position, for example such as above, below, on theside etc., also refer to the immediately described as well asrepresented drawing and with a change of position are to be appliedcorrespondingly to the new position. Furthermore, single features orcombinations of features from the different embodiments illustrated anddescribed may also represent, by themselves, independent, inventive orinvention-related solutions.

FIG. 1 shows a multi-speed gearbox comprising four planetary gear sets1, 2, 3, 4, an input drive shaft 70, a drive output shaft 71, six otherrotatable shafts 73, 74, 75, 76, 77, 78, six shift elements 51, 52, 61,62, 63, 64, of which there are two brakes 51, 52 and four clutches 61,62, 63, 64. The four planetary gear sets 1, 2, 3, 4 are disposed behindone another in the sequence: first planetary gear set 1, secondplanetary gear set 2, third planetary gear set 3, fourth planetary gearset 4. The first planetary gear set 1, the second planetary gear set 2,the third planetary gear set 3 and the fourth planetary gear set 4 areconstructed as minus planetary gear sets. The planetary gear sets 1, 2,3, 4 are jointly surrounded by a housing 72. In the variant of themulti-speed gearbox of FIG. 1:

-   -   a sun gear 41 of the fourth planetary gear set 4 is connected        with the housing 72 in a rotationally fixed manner,    -   a ring gear 13 of a first planetary gear set 1 is permanently        connected with a ring gear 43 of the fourth planetary gear set        4,    -   a sun gear 11 of the first planetary gear set 1 can be coupled        with the housing 72 via a first brake 51,    -   a carrier 12 of the first planetary gear set 1 can be coupled        with the housing 72 via a second brake 52,    -   the drive shaft 70 can be coupled with the sun gear 11 of the        first planetary gear set 1 via a first clutch 61    -   the output shaft 71 can be coupled with a carrier 42 of the        fourth planetary gear set 4 via a second clutch 62,    -   the drive shaft 70 can be coupled with the sun gear 21 of the        second planetary gear set 2 via a third clutch 63,    -   the drive shaft 70 can be coupled with the carrier 32 of the        third planetary gear set 3 via a fourth clutch 64,    -   the drive shaft 71 is permanently connected with the ring gear        33 of the third planetary gear set 3,    -   the ring gear 13 of the first planetary gear set 1 is        permanently connected with the sun gear 31 of the third        planetary gear set 3,    -   the carrier 12 of the first planetary gear set 1 is permanently        connected with the ring gear 23 of the second planetary gear set        2 and    -   ring gear 13 of the first planetary gear set 1 is permanently        connected with the carrier 22 of the second planetary gear set        2.

FIG. 2 shows a multi-speed gearbox that is very similar to themulti-speed gearbox of FIG. 1 and differs from the embodiment of FIG. 1in the following points:

-   -   the drive shaft 70 is permanently connected with the carrier 32        of the third planetary gear set 3 and    -   the output shaft 71 can be coupled with the ring gear 33 of the        third planetary gear set 3 via a fifth clutch 65.

FIG. 3 shows a multi-speed gearbox that is very similar to themulti-speed gearbox of FIG. 1 and differs from the embodiment of FIG. 1in the following points:

-   -   the drive shaft 70 is permanently connected with the carrier 32        of the third planetary gear set 3 and    -   the sun gear 31 of the third planetary gear set 3 can be coupled        with the shaft 74 via a sixth clutch 66.

FIG. 4 shows a multi-speed gearbox that is very similar to themulti-speed gearbox of FIG. 1 and differs from the embodiment of FIG. 1in the following points:

-   -   the drive shaft 70 is permanently connected with the sun gear 21        of the second planetary gear set 2 and—the carrier 12 of the        first planetary gear set 1 can be coupled with the ring gear 23        of the second planetary gear set 2 via a seventh clutch 67.

FIG. 5 shows a multi-speed gearbox that is very similar to themulti-speed gearbox of FIG. 4 and differs from the embodiment of FIG. 4in the following points:

-   -   the drive shaft 70 is permanently connected with the carrier 32        of the third planetary gear set 3 and    -   the drive output shaft 71 can be coupled with the ring gear 33        of the third planetary gear set 3 via a fifth clutch 65.

FIG. 6 shows a multi-speed gearbox that is very similar to themulti-speed gearbox of FIG. 4 and differs from the embodiment of FIG. 4in the following points:

-   -   the drive shaft 70 is permanently connected with the carrier 32        of the third planetary gear set 3 and    -   the sun gear 31 of the third planetary gear set 3 can be coupled        with the shaft 74 via a sixth clutch 66.

FIG. 7 shows a multi-speed gearbox that is very similar to themulti-speed gearbox of FIG. 1 and differs from the embodiment of FIG. 1in the following points:

-   -   the drive shaft 70 is permanently connected with the sun gear 21        of the second planetary gear set 2 and    -   the carrier 22 of the second planetary gear set 2 can be coupled        with the shaft 74 via an eighth clutch 68.

FIG. 8 shows a multi-speed gearbox that is very similar to themulti-speed gearbox of FIG. 7 and differs from the embodiment of FIG. 7in the following points:

-   -   the drive shaft 70 is permanently connected with the carrier 32        of the third planetary gear set 3 and    -   the drive output shaft 71 can be coupled with the ring gear 33        of the third planetary gear set 3 via a fifth clutch 65.

FIG. 9 shows a multi-speed gearbox that is very similar to themulti-speed gearbox of FIG. 7 and differs from the embodiment of FIG. 7in the following points:

-   -   the drive shaft 70 is permanently connected with the carrier 32        of the third planetary gear set 3 and    -   the sun gear 31 of the third planetary gear set 3 can be coupled        with the shaft 74 via a sixth clutch 66.

In the multi-speed gearbox represented in FIG. 1 the following gears canbe engaged:

A first gear can be implemented with the engaged first brake 51, theengaged second clutch 62 and the engaged third clutch 63.

A second gear can be implemented with the engaged second brake 52, theengaged second clutch 62 and the engaged third clutch 63.

A third gear can be implemented with the engaged first clutch 61, theengaged second clutch 62 and the engaged third clutch 63.

A fourth gear is implemented with the engaged second clutch 62, theengaged third clutch 63 and the engaged fourth clutch 64, or

with the engaged first brake 51, the engaged second clutch 62 and theengaged fourth clutch 64, or

with the engaged second brake 52, the engaged second clutch 62 and theengaged fourth clutch 64, or

with the engaged first clutch 61, the engaged second clutch 62 and theengaged fourth clutch 64.

A fifth gear is implemented with the engaged first clutch 61, theengaged third clutch 63 and the engaged fourth clutch 64.

A sixth gear is implemented with the engaged second brake 52, theengaged third clutch 63 and the engaged fourth clutch 64.

A seventh gear is implemented with the engaged first brake 51, theengaged third clutch 63 and the engaged fourth clutch 64.

An eighth gear is implemented with the engaged first brake 51, theengaged second brake 52 and the engaged fourth clutch 64.

A ninth gear is implemented with the engaged first brake 51, the engagedfirst clutch 61 and the engaged fourth clutch 64.

A reverse gear is implemented with the engaged first brake 51, theengaged first clutch 61 and the engaged second clutch 62.

At the same time, the respective shift elements not mentioned aredisengaged.

The table in FIG. 10 also shows this as it shows the transmission ratiosof the respective gear steps as well.

The shift positions of the multi-speed gearbox shown in FIG. 2 arecompletely similar to those of the multi-speed gearbox shown in FIG. 1but there the fifth clutch 65 takes the place of the fourth clutch 64.

The shift positions of the multi-speed gearbox shown in FIG. 3 arecompletely similar to those of the multi-speed gearbox shown in FIG. 1but there the sixth clutch 66 takes the place of the fourth clutch 64.

The shift positions of the multi-speed gearbox shown in FIG. 4 arecompletely similar to those of the multi-speed gearbox shown in FIG. 1but there the seventh clutch 67 takes the place of the third clutch 63.

The shift positions of the multi-speed gearbox shown in FIG. 5 arecompletely similar to those of the multi-speed gearbox shown in FIG. 4but there the fifth clutch 65 takes the place of the fourth clutch 64.

The shift positions of the multi-speed gearbox shown in FIG. 6 arecompletely similar to those of the multi-speed gearbox shown in FIG. 4but there the sixth clutch 66 takes the place of the fourth clutch 64.

The shift positions of the multi-speed gearbox shown in FIG. 7 arecompletely similar to those of the multi-speed gearbox shown in FIG. 1but there the eighth clutch 68 takes the place of the third clutch 63.

The shift positions of the multi-speed gearbox shown in FIG. 8 arecompletely similar to those of the multi-speed gearbox shown in FIG. 7but there the fifth clutch 65 takes the place of the fourth clutch 64.

The shift positions of the multi-speed gearbox shown in FIG. 9 arecompletely similar to those of the multi-speed gearbox shown in FIG. 7but there the sixth clutch 65 takes the place of the fourth clutch 64.

Preferably, all the gear sets 1, 2, 3, 4 in the multi-speed gearbox areimplemented as minus gear sets.

In an advantageous variant the transmission ratios are:

-   -   −1.850 between sun gear 11 and ring gear 13 of the first gear        set 1, and/or    -   −1.700 between sun gear 21 and ring gear 23 of the second gear        set 2, and/or    -   −1.700 between sun gear 31 and ring gear 33 of the third gear        set 3, and/or    -   −1.550 between sun gear 41 and ring gear 43 of the fourth gear        set 4.

In general, instead of an implementation of a first specifiedconnection/coupling to a carrier 12, 22, 32, 42 of a gear set 1, 2, 3, 4and a second specified connection/coupling to a ring gear 13, 23, 33, 43of this gear set 1, 2, 3, 4, the first specified connection/coupling maybe implemented to specified ring gear 13, 23, 33, 43 of this gear set 1,2, 3, 4 and the second specified connection/coupling to specifiedcarrier 12, 22, 32, 42 of this gear set 1, 2, 3, 4, wherein this gearset 1, 2, 3, 4 is implemented as a plus gear set instead of a minus gearset or as a minus gear set instead of a plus gear set, respectively. Inother words the connection/coupling to the carrier 12, 22, 32, 42 and tothe ring gear 13, 23, 33, 43 of a gear set 1, 2, 3, 4 is exchanged andthe direction of rotation between sun gear 11, 21, 31, 41 and ring gear13, 23, 33, 43 of gear set 1, 2, 3, 4 is reversed. It should also benoted that in the configuration of the multi-speed gearbox the value ofthe stationary transmission ratio is increased by 1 or decreased by 1,when the shiftable transmission ratios between input drive 70 and output71 should otherwise remain equal. By specified variations of the gearsets 1, 2, 3, 4 the connection/coupling between the individualtransmission elements can thus be changed without changing thecharacteristics of the transmission at the same time. Thereby severalstructural configurations are available, which can simplify theimplementation of the transmission in individual cases. Theabove-mentioned exchange of the connection/coupling is not limited toone gear set 1, 2, 3, 4, but can be applied to several gear sets 1, 2,3, 4 at the same time as well.

The embodiments show possible variations in the implementation of amulti-speed gearbox of the invention, wherein it should be noted herethe invention is not limited to the variations of implementationspecifically shown, but rather diverse combinations of the individualvariations of implementation are possible among themselves and thispossibility of variation lies within the ability of the person skilledin the art on the basis of the teaching of technical actions by means ofthe present invention. In particular, the possibilities that also resultfrom the combinatorics although not explicitly shown in the drawings,are included in the scope of protection. Moreover, the total conceivablevariations of implementation that are possible through combinations ofsingle details of the represented and described embodiment variationsare included in the scope of protection.

For the sake of order it is noted that, for better understanding of thedesign of the multi-speed gearbox, this is shown schematically in thedrawings and in reality can comprise more parts than shown, less partsthan shown or even other parts. In general, the concrete structuralconfiguration lies within the scope of the abilities of a person skilledin the art.

The problem underlying the independent inventive solutions can beinferred from the description.

REFERENCE NUMERALS

-   1 first transmission gear set-   2 second transmission gear set-   3 third transmission gear set-   4 fourth transmission gear set-   11 sun gear of the first transmission gear set-   12 carrier of the first transmission gear set-   13 ring gear of the first transmission gear set-   21 sun gear of the second transmission gear set-   22 carrier of the second transmission gear set-   23 ring gear of the second transmission gear set-   31 sun gear of the third transmission gear set-   32 carrier of the third transmission gear set-   33 ring gear of the third transmission gear set-   41 sun gear of the fourth transmission gear set-   42 carrier of the fourth transmission gear set-   43 ring gear of the fourth transmission gear set-   51 first brake-   52 second brake-   61 first clutch-   62 second clutch-   63 third clutch-   64 fourth clutch-   65 fifth clutch-   66 sixth clutch-   67 seventh clutch-   68 eighth clutch-   70 input drive-   71 output drive-   72 housing-   73, 74, 75, 76, 77, 78 shaft

1-13. (canceled)
 14. A multi-speed transmission comprising: an inputdrive shaft (70), an output shaft (71); at least first, second, thirdand fourth planetary gear sets (1,2,3,4) arranged within a housing (72),and each of the first, the second, the third and the fourth planetarygear sets comprising a sun gear, a ring gear, and a carrier; wherein thesun gear (41) of the fourth planetary gear set (4) is connected with thehousing (72) in a rotationally fixed manner; the ring gear (13) of thefirst planetary gear set (1) is permanently connected with the ring gear(43) of the fourth planetary gear set (4); the sun gear (11) of thefirst planetary gear set (1) is connectable with the housing (72), via afirst brake (51), the carrier (12) of the first planetary gear set (1)is connectable with the housing (72), via a second brake (52), the inputdrive shaft (70) is connectable with the sun gear (11) of the firstplanetary gear set (1) via a first clutch (61), the drive output shaft(71) is connectable with the carrier (42) of the fourth planetary gearset (4), via a second clutch (62); four connections of first, second,third, fourth, fifth and sixth connections are permanent connections anda remaining two connections of the first, the second, the third, thefourth, the fifth and the sixth connections are detachable connectionsfacilitated by at least one shift element: the first connection connectsthe input drive shaft (70) with the sun gear (21) of the secondplanetary gear set (2), the second connection connects the input driveshaft (70) with the carrier (32) of the third planetary gear set (3),the third connection connects the drive output shaft (71) with the ringgear (33) of the third planetary gear set (3), the fourth connectionconnects the ring gear (13) of the first planetary gear set (1) with thesun gear (31) of the third planetary gear set (3), the fifth connectionconnects the carrier (12) of the first planetary gear set (1) with thering gear (32) of the second planetary gear set (2), and the sixthconnection connects the ring gear (13) of the first planetary gear set(1) with the carrier (22) of the second planetary gear set (2).
 15. Themulti-stage transmission according to claim 14, wherein the input driveshaft (70) is connectable with the sun gear (21) of the second planetarygear set (2) via a third clutch (63); the carrier (12) of the firstplanetary gear set (1) is permanently connected with the ring gear (23)of the second planetary gear set (2); and the ring gear (13) of thefirst planetary gear set (1) is permanently connected with the carrier(22) of the second planetary gear set (2).
 16. The multi-stagetransmission according to claim 14, wherein the input drive shaft (70)is permanently connected with the sun gear (21) of the second planetarygear set (2); the carrier (12) of the first planetary gear set (1) isconnectable with the ring gear (23) of the second planetary gear set (2)via a third clutch (67); and the ring gear (13) of the first planetarygear set (1) is permanently connected with the carrier (22) of thesecond planetary gear set (2).
 17. The multi-stage transmissionaccording to claim 14, wherein the input drive shaft (70) is permanentlyconnected with the sun gear (21) of the second planetary gear set (2);the carrier (12) of the first planetary gear set (1) is permanentlyconnected with the ring gear (23) of the second planetary gear set (2);and the ring gear (13) of the first planetary gear set (1) isconnectable with the carrier (22) of the second planetary gear set (2)via a third clutch (68).
 18. The multi-stage transmission according toclaim 15, wherein the input drive shaft (70) is connectable with thecarrier (32) of the third planetary gear set (3) via a fourth clutch(64); the drive output shaft (71) is permanently connected with the ringgear (33) of the third planetary gear set (3); and the ring gear (13) ofthe first planetary gear set (1) is permanently connected with the sungear (31) of the third planetary gear set (3).
 19. The multi-stagetransmission according to claim 15, wherein the input drive shaft (70)is permanently connected with the carrier (32) of the third planetarygear set (3); the drive output shaft (71) is connectable with the ringgear (33) of the third planetary gear set (3) via a fourth clutch (65);and the ring gear (13) of the first planetary gear set (1) ispermanently connected with the sun gear (31) of the third planetary gearset (3).
 20. The multi-stage transmission according to claim 15, whereinthe input drive shaft (70) is permanently connected with the carrier(32) of the third planetary gear set (3); the drive output shaft (71) ispermanently connected with the ring gear (33) of the third planetarygear set (3); and the ring gear (13) of the first planetary gear set (1)is connectable with the sun gear (31) of the third planetary gear set(3) via a fourth clutch (66).
 21. The multi-stage transmission accordingto claim 18, wherein a plurality of gears can be implemented byselective engagement of three of the first brake, the second brake, thefirst clutch, the second clutch, the third clutch and the fourth clutchsuch that: a first gear is implemented by engagement of the first brake(51), the second clutch (62) and the third clutch (63); a second gear isimplemented by engagement of the second brake (52), the second clutch(62) and the third clutch (63); a third gear is implemented byengagement of the first clutch (61), the second clutch (62) and thethird clutch (63); a fourth gear is implemented by engagement of one of:the second clutch (62), the third clutch (63) and the fourth clutch (64,65, 66), the first brake (51), the second clutch (62) and the fourthclutch (64, 65, 66), the second brake (52), second clutch (62) andfourth clutch (64, 65, 66), and the first clutch (61), the second clutch(62) and the fourth clutch (64, 65, 66); a fifth gear is implemented byengagement of the first clutch (61), the third clutch (67) and thefourth clutch (64, 65, 66); a sixth gear is implemented by engagement ofthe second brake (52), the third clutch (67) and the fourth clutch (64,65, 66); a seventh gear is implemented by engagement of the first brake(51), the third clutch (67) and the fourth clutch (64, 65, 66); aneighth gear is implemented by engagement of the first brake (51), thesecond brake (52) and the fourth clutch (64, 65, 66); a ninth gear isimplemented by engagement of the first brake (51), the first clutch (61)and the fourth clutch (64, 65, 66); and a reverse gear is implemented byengagement of the first brake (51), the first clutch (61) and the secondclutch (62).
 23. The multi-stage transmission according to claim 20,wherein a plurality of gears can be implemented by selective engagementof three of the first brake, the second brake, the first clutch, thesecond clutch, the third clutch and the fourth clutch such that: a firstgear is implemented by engagement of the first brake (51), the secondclutch (62) and the third clutch (67); a second gear is implemented byengagement of the second brake (52), the second clutch (62) and thethird clutch (67); a third gear is implemented by engagement of thefirst clutch (61), the second clutch (62) and the third clutch (67); afourth gear is implemented by engagement of one of: the second clutch(62), the third clutch (67) and the fourth clutch (64, 65, 66), thefirst brake (51), the second clutch (62) and the fourth clutch (64, 65,66), the second brake (52), the second clutch (62) and the fourth clutch(64, 65, 66); and the first clutch (61), the second clutch (62) and thefourth clutch (64, 65, 66); a fifth gear is implemented by engagement ofthe first clutch (61), the third clutch (67) and the fourth clutch (64,65, 66); a sixth gear is implemented by engagement of the second brake(52), the third clutch (67) and the fourth clutch (64, 65, 66); aseventh gear is implemented by engagement of the first brake (51), thethird clutch (67) and the fourth clutch (64, 65, 66); an eighth gear isimplemented by engagement of the first brake (51), the second brake (52)and the fourth clutch (64, 65, 66); a ninth gear is implemented byengagement of the first brake (51), the first clutch (61) and the fourthclutch (64, 65, 66); and a reverse gear is implemented by engagement ofthe first brake (51), the first clutch (61) and the second clutch (62).24. The multi-stage transmission according to claim 14, wherein all thefirst, the second, the third and the fourth planetary gear sets (1, 2,3, 4) are minus planetary gear sets.
 25. The multi-stage transmissionaccording to claim 14, wherein a first connection to a carrier of aspecified one of the first, the second, the third and the fourthplanetary gear sets and a second connection to a ring gear of thespecified one of the first, the second, the third and the fourthplanetary gear sets are interchangeable, and the specified one of thefirst, the second, the third and the fourth planetary gear sets isimplemented either as a plus gear set or a minus gear set.
 26. Themulti-stage transmission of claim 18, wherein at least one of the secondclutch (62) and the third clutch (63, 67, 68) is a claw clutch.
 27. Amulti-speed transmission comprising: an input drive shaft; an outputshaft; first, second, third and fourth planetary gear sets arrangedwithin a housing, and each of the first, the second, the third and thefourth planetary gear sets comprising a sun gear, a ring gear, and acarrier; wherein the sun gear of the fourth planetary gear set isdirectly connected to the housing so as to prevent relative rotationtherebetween; the ring gear of the first planetary gear set is directlyconnected to the ring gear of the fourth planetary gear set so as toprevent relative rotation therebetween; the sun gear of the firstplanetary gear set is connectable, via a first brake, to the housing;the carrier of the first planetary gear set is connectable, via a secondbrake, to the housing; the input drive shaft gear of the first planetarygear set; the drive output shaft is connectable, via a second clutch, tothe carrier of the fourth planetary gear set; the input drive shaftconnects, via a first connection, with the sun gear of the secondplanetary gear set; the input drive shaft connects, via a secondconnection, with the carrier of the third planetary gear set; the driveoutput shaft connects, via a third connection, with the ring gear of thethird planetary gear set; the ring gear of the first planetary gear setconnects, via a fourth connection, with the sun gear of the thirdplanetary gear set; the carrier of the first planetary gear setconnects, via a fifth connection, with the ring gear of the secondplanetary gear set; the ring gear of the first planetary gear setconnects, via a sixth connection, with the carrier of the secondplanetary gear set; and four connections of the first, the second, thethird, the fourth, the fifth and the sixth connections are directconnections and two connections of the first, the second, the third, thefourth, the fifth and the sixth connections are releasable connectionsachieved by third and fourth clutches.
 28. The multi-stage transmissionaccording to claim 27, wherein a plurality of gears can be implementedby selective engagement of three of the first brake, the second brake,the first clutch, the second clutch, the third clutch and the fourthclutch such that: a first gear is implemented by engagement of the firstbrake, the second clutch and the third clutch; a second gear isimplemented by engagement of the second brake, the second clutch and thethird clutch; a third gear is implemented by engagement of the firstclutch, the second clutch and the third clutch; a fourth gear isimplemented by engagement of one of: the second clutch, the third clutchand the fourth clutch, the first brake, the second clutch and the fourthclutch, the second brake, second clutch and fourth clutch, and the firstclutch, the second clutch and the fourth clutch; a fifth gear isimplemented by engagement of the first clutch, the third clutch and thefourth clutch; a sixth gear is implemented by engagement of the secondbrake, the third clutch and the fourth clutch; a seventh gear isimplemented by engagement of the first brake, the third clutch and thefourth clutch; an eighth gear is implemented by engagement of the firstbrake, the second brake and the fourth clutch; a ninth gear isimplemented by engagement of the first brake, the first clutch and thefourth clutch; and a reverse gear is implemented by engagement of thefirst brake, the first clutch and the second clutch.